Automatic electrical cut-out.



'PATENTED JUNE 23, 1903.

. D. R. BRUCE. AUTOMATIC ELECTRICAL GUT-OUT.

APPLICATION FILED NOV. 18, 1902.

K kl w mmn UNITED STATES Patented June 23, 1903.

PATENT OFFICE.

AUTOMATIC ELECTRICAL CUT-OUT.

SPECIFICATION forming part of Letters Patent No. 731,428, dated June 23, 1903.

Application filed November 18, 1902. Serial No. 131,805. (No model.)

To all whom it may concern:

Be it known that I, DAVID ROBERTSON BRUCE, a citizen of England, residing at 2 Cottswell Villas, Hertford road, Ponders End, in the county of Middlesex, England, have invented a certain new and useful Automatic Electrical Out-Out, of which the following is a specification.

My invention relates to an automatic electrical cut-out, which I will describe, referring to the accompanying drawings, in which Figure l is a vertical longitudinal section,

- and Fig. 2 a plan.

A tube of non-conducting material a is'provided with a conductor 1;, which is free to movelongitudinallytherein. Thisconductor has at one end an arm I), of conducting material, projecting outside the tube a and secured on the conductor by means ot'a nut to. This armb is hinged to an insulated metal piece r on a base-plate d, the hinge being' provided. with a spring 6, which urges the other end of the tube a away from the base (Z. This spring 6 can be a blade-spring, as shown, ormay be a spring arranged in the hinge c". The other end of the conductor '21 is enlarged beyond the tube a, so as to form an arm f, also of conducting material, which is provided with an arm projecting downward, forming a hook m, that is engaged with a catch g, pivoted to anotherinsulating-piece 7L on the base 61. The arms I) and fare formed with lugs j j and It 10, respectively, on each side, in which are secured the conducting- .brushes I Z mm by means of set-screws 'n n o 0.

These conducting-brushes bear on two insulated contact-pieces p q, fixed on the base, which form terminals, to which are attached at s and t the two parts of the conductors to which the cut-out is applied. current consequently passes from brushes through arm b,conductor i, arm f, and brushes in m to contact q. The catch g forms one arm of a bell-crank lever mounted in the piece 7b, the other arm g of which can be pressed, more or less, down by means of an adjusting-screw 'IL, so that the catch 9 can be made to engage to a greater or less extent with the hook as, pivoted to the arm f. The

arm g is kept in its normal position by a spring o and is provided with a button forreleasing the catch g by hand when necessary.

When a current passes through the conducv tor 'i, it heats it, causing it and its arms I) and f to-expand, and when the current is excessive the corresponding increased expansion causes the armf to travel outward in a horizontal direction, thus causing the hook at to that when the cut-out is to be used for currents of greater intensity these parts are fully engaged together and for afoul-rent of less intensity they are only slightly engaged together, and the amount to which they are ongaged may be indicated by means of divisions on the adjusting-screw 21..

Having now particularly described the nature of this invention and the best means I know of carrying the same into practical effect, I clain1-'- p 1. An automatic electric cut-outconsisting of a tube of insulating material, a conductor passing through said tube having enlarged ends projecting beyond the tube constituting conducting-arms, devices on each otv said arms making contact respectively with one of the terminals of the circuit to be controlled, the one arm being pivoted to an insulated base and the other arm being provided with' a hook adapted to engage with a pivoted insulated catch so that on the expansion of the conductor due to heating by excessive current, it will push the hook out of engagement with the catch and a spring device whereby when such disengagement takes place, the tube with the conductor and its one arm are turned onthe pivoted armso as to break con- ICO the conductor under the heat of the current;

substantially as described.

3. In-an automatic electrical cut-ont, the

' combination of a conductor hinged at one end,insnlating material surrounding the conductor, contact-brushes attached at both ends of the conductor,a spring arranged to disengage both brushes, and a catch adapted to be disengaged by longitudinal expansion of the conductor under the heat of the current; substantially as described.

4. In an automatic electrical cut-out, the combination of a conductor hinged at one end and having an insulating-casing, contact-brushes attached to both ends of the conductor, a spring arranged to disengage the brushes, a catch arranged to be disengaged by longitudinal expansion of the conductor 1 under the heat of the current, and meansfor adjusting the catch to change its point of disengaging; substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing wit- :0 nesses.

D. R. BRUCE. Witnesses:

WALTER J SKERTEN, GERALD L. SMITH. 

